Photographic retouching opaque



United States Patent PHOTOGRAPHIC RETOUCHING OPAQUE William J. Rogers,Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., acorporation of New Jersey No Drawing. Application November 7, 1957Serial No. 694,924

2 Claims. (Cl. 106-162) This invention relates to photographicretouching opaque.

In the course of making photographic likenesses using conventionalphotographic equipment it is quite often desirable to retouch thenegative prior to making the finished print. In order to satisfactorilyretouch the negative, it is often mounted on an illuminated table orstand so that a diifused light enables a retoucher to eliminate spots,background, or the like in order to make the final print more attractiveto the subject of the photograph or for other purposes.

In order for an opaque to be satisfactory for retouching purposes, itmust be easy to apply, have a good flowing characteristic when appliedeither by pen or by brush, and a thin coating must be suflicientlyopaque to prevent light from passing through it during ordinaryphotographic printing processes.

In order to provide flexibility to the negative and to permit storage,the opaque must also have good aging characteristics so that upon dryingor upon being stored for a period of time, the retouched area will notchip or flake off the negative and the negatives can be reused forprinting purposes without requiring a new retouching operation.

In the past, various opaque formulations have been know such as thoseillustrated in various photographic textbooks and magazines; forinstance, the British Journal of Photography, September 29, 1916, onpage 533, discloses a retouching medium containing natural resins,turpentine, and the like. Wall and Jordan in Photographic Facts andFormulas," 1940, American Photographic Publishing Company, Boston,Massachusetts, on page 346, discloses a similar retouching medium.

Some of the prior art opaques do not mix easily with water duringdilution or have not been satisfactory for scribing so that lines couldnot be cut smoothly and evently. I have discovered a method of making asatisfactory opaque which has good adhesive characteristics and which issatisfactory for scribing, dilution, aging, and the like.

One object of this invention is to provide a plasticizer for aphotographic opaque which permits easy dilution with water. Anotherobject is to provide a plasticizer for photographic retouching mediawhich is satisfactory when the opaque is in a dried-down condition. Anadditional object is to provide a method of plasticizing photographicopaques with triethylene glycol.

In carrying out my invention, I mix triethylene glycol in the vehicle ofthe opaque in the amount of from 15% to 25% by weight, depending on thecharacteristics of the pigment with which the vehicle is mixed. Manypigments used in the manufacture of opaques, need more plasticizer thanothers due to their physical structure.

The following examples are intended to illustrate my invention but arenot intended to limit it to these pigments or to the components otherthan the trlehylene glycol plasticizer.

The vehicle is added to the pigment in a mechanical mixer. This mixtureis then ground on an ink mill untll uniformly smooth.

BLACK OPAQUE Example 2 Vehicle: G

Water 17.40 Triethylene glycol 8.40 Tamol (20% solution) .50 Gum arabic(55% solution) 9.08 Corn syrup 1.00 Phenol .08

36.46 Pigment: Graphite 13.75

Water '1' 6 Tamol .09

Vehicle is added to the pigment in a mechanical mixer and stirred untiluniform. It is then transferred to the ink mill and ground untilsufliciently smooth.

Variations can be made in the pigments so that opaque materials otherthan iron oxide or graphite can be used. For instance, white pigmentsmight be used such as zinc oxide titanium dioxide or the like. The onlyrequirement would be that the pigment be sufliciently opaque whencombined with the other materials to prevent light from passing throughthe negative.

Tamol is the sodium salt of sulfonated napthalene formaldehydecondensates.

I claim:

1. A red opaque containing water, corn syrup, the sodium salt ofsulfonated naphthalene formaldehyde condensates, gum arabic, phenol, ared pigment and 15-25% by weight of triethylene glycol.

2. A black retouching opaque containing water, the sodium salt ofsulfonated naphthalene formaldehyde condensates, gum arabic, corn syrup,phenol, black pigment and 15-25% by weight of triethylene glycol.

References Cited in the file of this patent UNITED STATES PATENTS1,811,384 Collier June 23, 1931 FOREIGN PATENTS 431,275 Great BritainJuly 4, 1935 OTHER REFERENCES Gregory: Uses and Applications ofChemicals and Related Materials, vol. II, 1944, page 336.

1. A RED OPAQUE CONTAINING WATER, CORN SYRUP, THE SODIUM SALT OFSULFONATED NAPHTHALENE FORMALDEHYDE CONDENSATES, GUM ARABIC, PHENOL, ARED PIGMENT AND 15-25% BY WEIGHT OF TRIETHYLENE GLYCOL.